Lat. In practice. A rule. Regula generalis, a general rule; a standing rule or order of a court. Frequently abbreviated, “Reg. Gen.” Regula Catoniana. In Roman law. The rule of Cato. A rule respecting the validity of dispositions by will. See Dig. 34, 7.
Regula est, juris quldem ignorantiam eulque nooere, fact! vero ignorantiam non nooere. Cod. 1, 18, 10. It is a rule, that every one is prejudiced by his ignorance of law, but not by his ignorance of fact